Treat the fire-bellied toad as a climber, not a ground toad
A fire-bellied toad enclosure fails when its owner assumes a toad stays on the floor, because fire-bellied toads climb glass corners, scramble up filter housings, and haul themselves onto floating plants that lift them toward the rim. Audit the enclosure from the toad's eye level: any route that reaches within a body length of the top is a ladder. Lower tall decor, move plants away from corners, and keep the water level low enough that a toad standing on its highest perch still cannot reach the lid line. Recheck after every rescape, since one new piece of cork bark leaning in a corner quietly rebuilds the escape staircase you removed.
The lid must be tight, clipped, and complete
A fire-bellied toad is stopped by a lid that fits inside the rim with no flex, secured with clips or weight at both ends, because a light screen top lifts easily when a toad pushes from a perch below. Inspect corners closely, as lids often bow or sit slightly proud exactly there, leaving the one gap a small toad needs. Cover any cut-outs made for filter pipes and cables with fine mesh fixed firmly in place, and never leave a section of the top open for ventilation on the assumption that the toad cannot reach it. Humidity stays high in a mostly covered toad enclosure anyway, so a complete lid costs the toad nothing it needs. Test the closed lid with a firm upward push at each end before you trust it overnight, because a lid that shifts under your hand will certainly shift under a climbing toad working the same corner for an hour.
Mind the water section during every change
A fire-bellied toad most often escapes during water changes, when the lid is off, the water is disturbed, and the toad is active and climbing. Move the toad to a secure, ventilated holding tub with a damp floor before you open the enclosure fully, rather than working around it. Keep the holding tub's lid on and weighted during the whole job, because a fire-bellied toad in a strange container tests its edges immediately. Work with the room door closed and a towel along its base, so a toad that does get loose stays in one searchable room. Return the toad only after the enclosure lid is ready to close behind it.
Search low, dark, and damp if one gets out
A fire-bellied toad loose in a room travels low and seeks moisture, ending up under furniture, behind the enclosure stand, or in the damp corner near sinks and pipes. Search slowly with a torch at floor level, moving objects gently, because a startled toad wedges itself deep into the first crevice it reaches. Place a shallow dish of dechlorinated water with a ramp of damp paper towel on the floor overnight, since a drying toad will find and use it. Keep other pets shut out of the room, as a fire-bellied toad's skin is noxious and a curious dog or cat could be harmed by mouthing it. If the toad may have reached a hallway or beyond, KinsLe's Lost Pet Alert System can alert nearby members so whoever spots it can message you directly.